The present invention relates to a method and apparatus for programably treating water (preferably refrigerated) in a water cooler and more particularly to an improved method and apparatus for sanitizing water that is to be dispensed from a water cooler of the type having a cabinet with one or more spigots from a reservoir water supply that is hidden inside the cabinet.
There are several types of cabinet type water dispensers in use today. One of the most common types of such water dispensers is a floor standing cabinet having an open top that receives a large inverted bottle. The bottle is typically of a plastic or glass material having a constricted neck. The bottle is turned upside down and placed on the top of the cabinet with the neck of the bottle extending into a water filled reservoir so that the water seeks its own level in the reservoir during use. As a user draws water from a spigot dispenser, the liquid level in the reservoir drops until it falls below the neck of the bottle at which time water flows from the bottle and bubbles enter the bottle until pressure has equalized. Inverted bottle type water dispensers are sold by a number of companies in the United States and elsewhere. Many are refrigerated.
Other types of water dispensers have an outer cabinet that contains a reservoir or water supply. These other types of water dispensers having a cabinet include one type that stores a large bottle (such as three or five gallon) at the bottom of the cabinet. A pump transfers water from the large bottle to the reservoir. At the reservoir, the water is typically refrigerated.
Another type of water dispenser simply connects a water supply (e.g., city water, well water) directly to a reservoir that is hidden inside the cabinet. A float valve or other water level controller can be provided to insure that the reservoir is always filled with water but does not overflow. Water that is transferred from city water, well water or another source can be filtered or otherwise treated before being transmitted to the reservoir.
All of these types of water dispensers that employ cabinets typically have one or more water dispensing spigots on the outside of the cabinet. These spigots are typically manually operated, but can be automatically operated. For example, water vending machines dispense after a consumer pays for water. The water is automatically dispensed when coins are fed to the machine.
One of the problems with cabinet style water dispensers is that of cleansing the reservoir from time to time. Because the reservoir is not air tight, it breathes allowing bacteria to enter the reservoir over a period of time. The reservoirs are typically contained within the confines of the cabinet and are not easily accessed and cleaned by consumers or end users.
For inverted bottle type dispensers, in addition to the problem of an open top, the five gallon bottles are themselves a source of bacteria and germs. Most of these bottles are transported on trucks where the bottles are exposed to outside air. They are handled by operators that typically grab the bottle at the neck, the very part of the bottle that communicates with the open reservoir during use. Unfortunately, it is difficult to convince every person that handles these bottles to wash their hands frequently enough. In order to properly sanitize such a water dispenser or cooler, the user must carefully clean the neck of the bottle prior to combining the bottle with the cabinet. Further, the user should drain and sanitize the reservoir from time to time. The cleansing of the reservoir in such a water dispenser is a time consuming project that is typically not performed at regular intervals.
The dispensing spigots that are provided on common cabinet type water dispensers can also be a source of contamination. These spigots are typically manually operated and are therefore a source of contamination from the users that operate them. Individuals have also been known to drink directly from the spigot. Therefore, sanitation of the spigots as well as the reservoir should be a part of routine maintenance.
Process ozone diffusion by bubble reactor method in small static volumes of water with abbreviated water columns to diffused ozone levels satisfactory to disinfect microorganisms in brief time periods can be difficult to achieve. An ozone generator can be used as the source of ozone. The ozone generator can include an air pump as a source of oxygen for generating ozone. The air pump preferably includes a microbial filter to filter contaminants. A diffuser can be used to diffuse the generated ozone into the water reservoir.
Various factors impact the effectiveness of bacterial removal from the water such as the microbial load, pH, temperature, conductivity, and cooler characteristics (e.g., whether an ice ring has formed which can act as a shield for microbes trapped in the ice ring). Furthermore, the variability of power supply (e.g., European power supplies versus US power supplies) can cause a generator's application to be geographically limited unless modified. Additionally, time constraints for operation of the ozone generator and diffuser can impact operation.
Additionally, in certain refrigerated reservoirs an ice ring can form inside the reservoir adjacent to the cooling coils for the reservoir. Such an ice ring can serve as a form of protection for microbes contained in the ice ring when ozone is being diffused in the reservoir. After an ozone cycle, when the ice melts wholly or partially, the trapped microbes can enter the water and thus contaminate the reservoir.
Additionally, certain waters contain loadings of bromates which can cause problems.
The above indicate a need for developing a generator and diffuser containing flexibility regarding the timing, amount, and duration of ozone generated; along with the timing, amount, and duration of air supplied. Additionally, there is a need for killing microbes which may be trapped in ice rings. Furthermore, there is a need for addressing water containing bromates. Additionally, there is a need for addressing different types of electrical supplies for various geographical areas.
In a preferred embodiment the method and apparatus is directed to an economical means of overcoming each of the factors that limit process ozone's potential disinfecting capacity. It is concerned with the optimization of each point in small automated ozonation systems both upstream and downstream from the ozonator. The object of this effort is to devise a single, economical, high longevity system capable of sanitizing many of the shapes and sizes of water dispensers in use today.
The present invention thus provides an improved self sanitizing water dispenser apparatus as well as a method for generating ozone for cleaning the reservoir and the water contained within it.
While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”